Surface apparatus for handling an elastic column

ABSTRACT

This apparatus is provided with at least two devices for gripping an elastic column, including a lower and an upper gripping devices, one at least of these devices being displaceable along the axis of the column in a released position. In this apparatus each of said devices is constituted by a plurality of separate gripping elements arranged in series and means are provided for suspending these gripping elements from one and the same support member, permitting relative displacement of said gripping elements with respect to one another along the axis of the elastic column, under the action of the load to which each gripping element is subjected.

United States Patent Remi Reynard Montessori;

Roger Tindy, Bougival; Edmond Daniel, Saulx-les-Chartreaux, all of, France Inventors SURFACE APPARATUS FOR HANDLING AN ELASTIC COLUMN 10 Claims, 7 Drawing Figs.

U.S. Cl 226/115,

226/150, 226/162, 294/88, 214/25 Int. Cl B65h 17/36 Field of Search 226/150, 162, I08, I15; 294/86, 88; 214/25 References Cited v UNITED STATES PATENTS 2,841,961 7/1958 Lucas 294/86 X 2,967,008 1/1961 .lohansson 226/108 3,133,469 5/1964 Ljungberg 226/150 X Primary Examiner-Allen N. Knowles Attorney-Craig, Antonelli and Hill ABSTRACT: This apparatus is provided with at least two devices for gripping an elastic column, including a lower and an upper gripping devices, one at least of these devices being displaceable along the axis of the c'olumn in a released position.

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SHEET 3 OF 4 INVENTOP Rom wna d Q0 mm Ed OHADA QQJ BY em mmw Ww ATTORNEYS SURFACE APPARATUS FOR HANDLING ANELASTIC COLUMN The present invention relates to a surface apparatus whereby an elastic column, particularly a column introduced into a borehole drilled through the ground can be handled, i.e. lowered into the borehole and raised back to the ground surface.

This column may, for example, by a flexible drill pipe used in the drilling process wherein is substituted for the usual string of rigid stems a continuous flexible pipe at the lower end of which a bottom motor is directly connected to a drill bit for actuation thereof.

It is however also possible to use the apparatus according to the invention for handling a column or an elongated member of solid structure lowered in a borehole, such as a cable liable to undergo some elongation under its working conditions.

The handling apparatus according to the invention is of a type provided with devices for gripping the elastic column, some of these gripping devices being movable along the column.

A first object of the invention is to provide an apparatus which may be associated with conventional equipments used in conventional drilling methods, such as derricks, hoisting devices using winches, cables and pulley blocks, without requiring any substantial change in these equipments.

The main object of the invention is to provide an apparatus for handling an elastic column capable of supporting loads which may reach many hundred tons, with an elongation of this column, relative to the gripping device, under the action of the load, which does not lead to deteriorations of the walls of this column which are in contact these gripping devices, or to creeping phenomena of this column, relative to the gripping devices applied thereto.

The apparatus according to the invention, whereby are achieved these objects, includes at least two devices for gripping the elastic column, .comprising a lower and an upper gripping devices, each of said devices being associated with means for displacing at least one of said devices parallelly to the column axis, means for sequentially controlling said displacing means and for generating a gripping action on said column through either of said gripping devices, so that there is always at least one of said gripping devices in its gripping position, the displacement of said gripping devices being effected in a first direction in the gripping position of the device and in the opposite direction in the released position of this device.

According to the invention, each of said upper and lower devices for gripping the column is constituted by a plurality of separate elements, or gripping belts, arranged in series, suspended from one and the same support means, adapted to permit a relative displacement of said gripping belts with respect to each other, under the action of the load to which each of said gripping belt is subjected.

A nonlimitative embodiment of the invention is described hereinunder, with reference to the attached drawings wherein:

FIG. I diagrammatically illustrates an overall view of the apparatus;

FIG. 2 illustrates a gripping belt;

FIGS. 3, 3a and 3b diagrammatically illustrate an embodiment of the means according to the invention for suspending the gripping belts in each of the lower and upper gripping devices;

FIG. 4 diagrammatically shows the relative displacement of the gripping belts, permitted by the arrangement according to the invention; and

FIG. 5 diagrammatically illustrates an embodiment of the synchronized control means of the apparatus.

In FIG. I which diagrammatically shows an overall view of a drilling equipment for a flexible drill pipe including an ap- The pipe 1 is stored on a winch 4 associated with means for supplying the pipe with drilling fluid through a rotary coupling and passes between this winch and pulley 3 through a tension regulating device diagrammatically represented at 5, the winch 5 and the tension regulating device 5 forming however no part of the present invention.

The apparatus according to the invention, used for handling the flexible pipe I comprises a lower device 6 for gripping this pipe, this lower gripping device being constituted by a series of gripping belts each of which is provided with gripping jaws and with a device for moving these jaws into and out of gripping position, adapted for reversibly displacing them between a gripping position of the pipe I and a released position enabling the pipe to freely slide between the jaws and giving passage to the rigid metallic elements connected to the lower part of the flexible pipe, these elements comprising the drill bit and the motor for driving this bit.

This lower gripping device 6 is stationary, being integral with the substructure 7 of the derrick.

In combination with this stationary lower gripping device, the apparatus according to the invention includes an upper gripping device 8 for the pipe I, this device being also constituted by a series of gripping belts, each of which is provided with jaws associated with a reversible device for displacing these jaws in a direction transverse to the pipe. This upper device is movable vertically over a stroke Lalong the pipe, in the released position of its jaws.

In the embodiment illustrated by FIG. 1, the means providing for the displacement of the upper gripping device 8 of the pipe along this pipe I is constituted by a hoisting device of the type used in the rotary drilling method for handling the drill string and its elements.

This device includes cables 9 passing over a'stationary pulley block 10 located at the top of the derrick (this stationary pulley block includes for example two pulleys located on both sides of pulley 3) and over a traveling block 11 from which is suspended the upper gripping device 8, by means of a hook 12. The vertical displacements of the traveling block 11 are achieved by means ofa winch 13 on which is wound a free end 9a of cables 9. i

The adaptation of this conventional hoisting device to the embodiment illustrated by FIG. 1 of the apparatus according to the invention for handling a flexible pipe is achieved by providing an axial passage such as 14 through the traveling block 11 and axial bores through the hook 12, this passage and these bores having a sufficient diameter for giving a free passage to the flexible drill pipe.

In combination with the above-indicated elements, the device according to the invention includes means for synchronously controlling on the one hand the means for displacing the upper gripping device 8 (winch 13 in the illustrated embodiment) and on the other hand the means for moving the jaws of the two gripping devices 6 and 8 into and out of gripping position.

These control means, which are not shown on FIG. I, will be described hereinunder, with reference to FIG. 4.

These means are adapted to repeatably provide for either of the two following series ofoperations:

l-RAISING OF THE PIPE Simultaneous gripping of the pipe by the jaws of the two I gripping devices 6 and 8, when the upper gripping device is in its lower position, substantially in contact with the device 6.

2. Releasing of the jaws of the lower gripping device 6, the upper gripping device remaining in its gripping position.

3. Actuating the hoisting winch I3 in the direction for raising the upper gripping device 6.

4. Stopping this upper gripping device in its uppermost position at the upper end of its stroke L.

5. Moving the jaws of the lower gripping device into gripping position, then releasing the jaws of the upper III .OWERING OF THE PIPE Simultaneous gripping of the pipe by the jaws of the two devices 6 and 8, while the upper gripping device is in its upper position at the top of the derrick.

2. Releasing of the jaws of the lower gripping device 6, the upper gripping device 8 remaining in its gripping position.

3. Downwardly moving the device 8 under the load of the flexible pipe with braking of this movement, for example through winch l3.

4. Stopping the device 8 in its lowermost position.

5. Moving the jaws of the device 6 into gripping position then releasing the jaws of the device 8, while the jaws of the device 6 remain in their gripping position.

6. Raising back the device 8 without load up to its uppermost position and stopping it in this position.

7. Moving the jaws of the device 8 into gripping position, in

the upper position of this device.

FIG. 2 diagrammatically illustrates the structure of an element or gripping belt constituting each of the gripping devices 6 and 8.

This element includes at least two gripping jaws for the pipe 1 (jaws l and 16) which may grip the pipe 1 by means of reversible hydraulic jacks 17a, 17b which bear against a tubular housing 18 whereon these jacks are articulated.

The jaws l5 and 16 roll on rollers along inclined guide paths integral with this tubular housing.

These jaws and their guide paths constitute and automatic gripping system so designed as to exert on the pipe a gripping action always proportional to the downwardly directed vertical force (indicated by the arrow in FIG.'2) to which it is subjected as a result of friction between the jaws and the pipe, this arrangement being a safety factor.

In the examplative embodiment of FIG. 2, each of the jaws l5 and 16 is constituted by two superimposed wedges integral with each other.

The reference numerals 37, 38, 39 and 40 designate rollers the axes of which are carried by jaws l5 and 16, these rollers rolling along inclined guide paths 41 to 44 carried by the tubular housing 18.

Each gripping element or belt may obviously be provided with more than two gripping jaws, distributed along the periphery of the flexible pipe 1.

Inside each gripping belt, such as the one shown by FIG. 2, the relative elongation of the pipe I, with respect to the gripping jaws will be reduced since each gripping belt only supports a fraction of the overall load supported by each of the gripping devices 6 and 8 and because moreover the length of the pipe 1 passing through this belt is only a fraction of the overall length of the pipe I, passing through each of the gripping devices 6 and 8.

In order to permit some relative displacement without any creeping of the pipe 1 inside each gripping jaw, it will be advantageous to provide each gripping jaw such as jaw or jaw 16, with an internal coating or shoe made of an elastomer on the internal wall of this jaw which comes into contact with pipe 1, or to fix the shoe to a pad made of an elastic material, such as an elastomer.

FIGS. 3, 3a and 31) show the arrangement according to the invention of the gripping belts constituting each of the gripping devices 6 and 8.

In the illustrated embodiment the belts mounted in series are four in number, but this number should by no way be considered as limitative.

The number n of gripping elements or belts constituting each gripping device will be selected sufficiently high so that,

taking into account the coefficient of elongation of the column or pipe and the maximum load W to be supported by the lower and upper gripping devices, the maximum load W/n to be supported by each gripping belt will correspond to a tolerable elongation of the portion of column passing through this gripping element.

The different elements or belts for gripping the column 1 (elements 18b, 18c, 18d) arranged in series for constituting each of the gripping devices 6 and 8 of FIG. 1 are suspended through rocking levers such as the rocking levers 21 and 22 (FIGS. 3 and 3a) from one and the same support member 23, by means of rods 124a, 124b, 1240, 124d for the rocking lever 21 and of corresponding rods for the rocking lever 22.

The lower end of each suspension rod is connected through a ball and socket joint to the element which this rod supports. for example at 26 for the rod 124a.

The displacement of each gripping belt with respect to the adjacent belt is limited by a slot 127a provided on one ofthese belts, a stud 128a integral with the other belt being vertically displaceable within this slot.

The assembly of the gripping belts is contained in a housing 29 internally provided with means, such as rollers 30, 31 32 and 33, for guiding the gripping belts.

If these belts constitute the movable upper gripping device 8 (FIG. 1 the housing 29 will be suspended from hook 12.

Such an arrangement enables the gripping belts to perform relative vertical movements through the inclination of the rocking levers, permitted by the ball and socket joints to 136, following (FIG. 4) the elongation of the pipe under the action of the weight W applied to this pipe.

An embodiment of the means for synchronously controlling the hoisting winch l3 and the jacks which provide for moving the jaws into and out of gripping position is described hereinunder with reference to FIG. 5.

The reversible jacks 21a to 28a controlling the jaws 21b to 28b of the upper gripping device 8 and the jacks 29a to 36a of the jaws 29b to 36b of the lower gripping device 6 are supplied with hydraulic fluid from a tank 45 by means ofa motor-pump unit P through two slide valves 46 and 47 which are mechanically interconnected, so as to be displaced synchronously.

This connection is diagrammatically indicated by a rod 48 in FIG. 5.

An arm 49 providing for electrical contact and forming a T with the connecting rod 48 integral with this arm provides for synchronous control of the actuation of the winch l3 and of that of the jaws, by closing electrical contacts: contact M for actuating the winch so as to raise the movable upper gripping device 8, contact 0 for stopping the winch and contact D for disconnecting the winch 13, so as to enable the device 8 to be lowered under the action of the load, with a braking effect performed by the winch.

The movements of the assembly of the slide valves 46 and 47 are controlled through an electrovalve 50 which, by admission of hydraulic fluid onto either of the end faces 51 and 52 of this assembly of slide valves, through the conduits shown is dotted line in FIG. 5, cause the displacement of this assembly of slide valves either to the right or to the left of the drawing.

In the hydraulic circuit of FIG. 5, F designates a filter, the device such as 53 and 54 are nonreturn valves, 55 a pipe supplying hydraulic fluid makeup so as to compensate for the losses in the hydraulic circuit (this makeup supply of fluid is for example achieved from gauged oleopneumatic accumulators) and 56 designates a safety valve.

The device such as 57 and 58 are device for regulating the flow rate of the hydraulic fluid supplied to the jacks during gripping or releasing movement of the jaws respectively.

It appears that the position shown in FIG. 5 of the assembly of the control slide valves 46 and 47 corresponds to the gripping position of the jaws of the two gripping devices 6 and 8, the winch 13 being stopped (arm 49 on contact 0), which corresponds to the stopping of the movable upper gripping element 8.

By moving to the right of FIG. 5 the assembly of the two distributing slide valves 46 and 47 (which is achieved by controlling the electrovalve 50 so as to move its slide to the left), the jaws of the lower gripping device 6 are moved away from each other, while the jaws of the upper gripping device 8 remain the their gripping position.

The arm 49 for electric contact comes onto the contact M, which so actuates the winch 13 as to raise the gripping device 8.

A not illustrated device, such as an electric retarding device, may be used so that the actuation of winch 13 be efing slide valves 46 and 47, by electrically controlling the elec-.

trovalve 50 displacing the slide of this electrovalve toward the left of the drawing, the jaws of the upper gripping element 8 are moved away from each other while those of the lower element 6 remain in their gripping position.

By electrically controlling the electrovalve 50, it is thus possible to perform the different operations, the succession of which following a predetermined order, enables the lowering or raising of the flexible drill pipe to be achieved.

This control may either be manual, by actuating an electrical switch (not shown) or made fully automatic by using a programming device which may be of any suitable known type, for example a drum driven in rotation at a constant speed and provided around its periphery with electrical contacts having the shape of annular sectors which will successively actuate, at predetermined instants which are functions of their respective positions on the drum, a switch located in the immediate vicinity of this drum and controlling the electrovalve 50. This programming may also be achieved by automatic controlling based on the displacements of the upper gripping device, for example by means of photoelectric cells located at suitable levels, at the upper and lower ends of the stroke of this upper gripping device.

It has been assumed in the foregoing that the gripping action by each of the gripping devices 6 and 8 is performed by moving simultaneously the different jaws of these devices into gripping position.

It will also be possible to so constitute the gripping means of the jaws that the weight W of the flexible line 1 which is supported by each of the gripping devices 6 and 8 alternatively (this weight varying moreover as a function of'the unreeled length of the flexible pipe) is taken up by successively moving into gripping position the different belts which constitute each of these devices (dephased" gripping), by first moving into gripping position in each gripping belt the belt whose displacement, under the action of the load, is the smallest, the belts being moved out of gripping position by following the reverse order. This will make it possible for the flexible pipe to expand below each gripping belt, under the action of the fraction of the weight W which is supported by this belt and by the belts which are already in their gripping position, thereby reducing the relative displacement resulting from a sliding motion or creeping or from a deterioration of the wall ofthe flexible pipe within this belt.

In practice, since the gripping action by each belt becomes effective only after some time from the instant of actuation of the jacks such as 17a, 17b (automatic clamping action of the flexible pipe by the jaws l5 and 16, FIG. 2), there will be some overlapping of the periods for successively moving into gripping position the belts of each device 6 and 8, so as to not overload any gripping belt.

Assuming for example that the overall load W is 200 tons and each of the devices 6 and 8 includes four gripping belts, i.e. the maximum load which is to be supported by each belt is 50 tons, the gripping the the flexible pipe 1 by the upper gripping element 8 in the lowermost position of the latter may be achieved by first moving into gripping position the jaws 21b and 22b (FIG. 5) of the upper belt of this gripping device and by increasing through actuation of the winch the load sup ported by this belt up to about 40 tons, after the automatic clamping action has been initiated, while the lower gripping element 6 is at the same time progressively unloaded.

The jaws 23b, 24b of the nearest lower belt are then moved into gripping position without waiting" that the jaws 21b, 22b have reached their maximum load of 50 tons.

Similarly, as soon as the fraction of the weight W supported by the assembly of the jaws 21b, 22b and 23b, 24b reaches about 502 40x tons, the jaws 25b, 26b are moved into gripping position etc....

This method of gripping, wherein a belt is placed into gripping position without waiting that the previously actuated belt has reached its maximum load, results in an elongation of the pipe between these two belts, with respect to its position at the instant of the beginning of the gripping action by the lower belt, such an elongation occurring during the above-defined overlapping period (for example when the load of the upper belt of the gripping device continues to increase from the value 40 tons, corresponding to the beginning of the gripping action of the next belt, up to its maximum value 50 tons).

The arrangement, according to the invention, of the gripping belts inside each of the gripping devices 6 and 8, such as illustrated in FIG. 3, permits a relative displacement of the belts, corresponding to the elongation of the flexible pipe between these belts in there gripping position.

Various modifications may be made without departing from the scope of the invention.

For example both gripping devices may be movable along the axis of the pipe over a stroke C, so that the displacement of one of the gripping devices in its released position is effected during the displacement of the other gripping device in its gripping position.

It will also be possible, for example, to use three gripping devices arranged in series, the intermediate gripping device being stationary with respect to the drilling rig, while the upper and lower gripping devices are movable along the axis of the column or flexible pipe.

It will also be possible to take advantage of the phenomenon of automatic clamping by each gripping belt by substituting single acting jacks for the double acting jacks actuatingthe gripping jaws in the embodiment of FIG. 5, these single acting jacks releasing the pipe by moving the jaws away from the axis of the column, while elastic means, such as for example springs, move automatically the jaws toward each other, i.e. into their gripping position, when the jacks are not actuated,

What we claim is:

l. A surface apparatus for handling an elastic column, provided with at least two devices for gripping the elastic column, including a lower gripping device and an upper gripping device, each of said gripping devices being associated with means for placing said devices into and out of gripping position, means for displacing at least one of said gripping devices along the axis of the column, means for sequentially actuating said displacing means, adapted to always maintain at least one of said gripping devices in its gripping position and to perform the displacement of said gripping device successively in a first direction corresponding to the gripping position of this device and in the opposite direction corresponding to the released position of said gripping device, each of said gripping devices being constituted by a plurality of separate gripping elements arranged in series and means for suspending each of said gripping elements from one and the same support member permitting the relative displacement of said gripping elements with respect to one another along the axis of the elastic column under the action of the load to which each of said gripping elements is subjected.

2. An apparatus according to claim 1, wherein said suspension means is constituted by an assembly of rigid rods so articulated as to form a system of rocking levers permitting the relative displacement of said gripping elements through the inclination of said rocking levers.

3. An apparatus according to claim I, wherein each of said gripping devices includes a housing wherein are located said gripping elements, said housing being adapted for guiding said gripping elements during their displacement along the axis of the elastic column.

4. An apparatus according to claim 3, wherein said housing is provided with guide paths parallel to the axis of the column and wherein said gripping elements are provided on their external wall with rollers adapted, by cooperating with said guide paths, to permit the relative displacement of the gripping elements, with respect to said housing, along the axis of the elastic column.

5. An apparatus according to claim 1, wherein said gripping element includes a housing provided with means for gripping the elastic column, said gripping means including at least two gripping jaws having a gripping surface substantially parallel to the axis of the column, each of said jaws being slidable along'a guide path integral with said housing and inclined with respect to the column axis so as to downwardly come closer to this axis, thereby being adapted to perform an automatic clamping action on the elastic column, when the latter is subjected to a vertical downwardly directed tension, each of said jaw being actuated by jack means articulated to said housing and to said jaw, said jack means being adapted to move the jaw closer to the axis of the elastic column in its gripping position and to move the jaw away from this axis in its released position.

6. An apparatus according to claim 5, wherein each of said jaws is provided with at least one roller which can roll along said inclined guide path.

7. An apparatus according to claim 5, wherein said gripping surface of each jaw is adapted to partly cover the external surface of said elastic column, said gripping surface being coated with an elastomer lining.

8. A apparatus according to claim 5, wherein said jack means is adapted to move said jaw away from the axis of the elastic column against the action of an elastic device adapted to automatically move said jaw toward this axis in the absence of any action of said jack means on said jaw.

9. A method for operating a device according to claim 1, wherein in each gripping device is successively actuated a first of said element for gripping the elastic column. said first element being that for which the displacement relative to its initial position, as a result of the applied load, is the smallest, then is actuated the gripping element adjacent to said first gripping element when said first element is substantially in its gripping position, and so on for the different gripping elements of said gripping device.

10. A method according to claim 9, wherein gripping of the elastic column by said adjacent gripping element is performed before said gripping element has fully reached its gripping position, when the load supported by said first gripping element has reached a predetermined fraction of its final load in its position of full gripping. 

1. A surface apparatus for handling an elastic column, provided with at least two devices for gripping the elastic column, including a lower gripping device and an upper gripping device, each of said gripping devices being associated with means for placing said devices into and out of gripping position, means for displacing at least one of said gripping devices along the axis of the column, means for sequentially actuating said displacing means, adapted to always maintain at least one of said gripping devices in its gripping position and to perform the displacement of said gripping device successively in a first direction corresponding to the gripping position of this device and in the opposite direction corresponding to the released position of said gripping device, each of said gripping devices being constituted by a plurality of separate gripping elements arranged in series and means for suspending each of said gripping elements from one and the same support member permitting the relative displacement of said gripping elements with respect to one another along the axis of the elastic column under the action of the load to which each of said gripping elements is subjected.
 2. An apparatus according to claim 1, wherein said suspension means is constituted by an assembly of rigid rods so articulated as to form a system of rocking levers permitting the relative displacement of said gripping elements through the inclination of said rocking levers.
 3. An apparatus according to claim 1, wherein each of said gripping devices includes a housing wherein are located said gripping elements, said housing being adapted for guiding said gripping elements during their displacement along the axis of the elastic column.
 4. An apparatus according to claim 3, wherein said housing is provided with guide paths parallel to the axis of the column and wherein said gripping elements are provided on their external wall with rollers adapted, by cooperating with said guide paths, to permit the relative displacement of the gripping elements, with respect to said housing, along the axis of the elastic column.
 5. An apparatus according to claim 1, wherein said gripping element includes a housing provided with means for gripping the elastic column, said gripping means including at least two gripping jaws having a gripping surface substantially parallel to the axis of the column, each of said jaws being slidable along a guide path integral with said housing and inclined with respect to the column axis so as to downwardly come closer to this axis, thereby being adapted to perform an automatic clamping action on the elastic column, when the latter is subjected to a vertical downwardly directed tension, each of said jaw being actuated by jack means articulated to said housing and to said jaw, said jack means being adapted to move the jaw closer to the axis of the elastic column in its gripping position and to move the jaw away from this axis in its released position.
 6. An apparatus according to claim 5, wherein each of said jaws is provided with at least one roller which can roll along said inclined guide path.
 7. An apparatus according to claim 5, wherein said gripping surface of each jaw is adapted to partly cover the external surface of said elastic column, said gripping surface being coated with an elastomer lining.
 8. A apparatus according to claim 5, wherein said jack means is adapted to move said jaw away from the axis of the elastic column against the action of an elastic device adapted to automatically move said jaw toward this axis in the absence of any action of said jack means on said jaw.
 9. A method for operating a device according to claim 1, wherein in each gripping device is successively actuated a first of said element for gripping the elastic column, said first element being that for whiCh the displacement relative to its initial position, as a result of the applied load, is the smallest, then is actuated the gripping element adjacent to said first gripping element when said first element is substantially in its gripping position, and so on for the different gripping elements of said gripping device.
 10. A method according to claim 9, wherein gripping of the elastic column by said adjacent gripping element is performed before said gripping element has fully reached its gripping position, when the load supported by said first gripping element has reached a predetermined fraction of its final load in its position of full gripping. 